Windmills have provided useful power for at least 600 years. However, utilization of wind energy in the United States and elsewhere has declined. The problem with utilization of wind energy is the vast disparity of wind velocities which will confront a wind energy system.
The power of wind varies as the cube of the velocity. There are relatively few areas in the United States where the wind routinely exceeds 10 m.p.h. Thus, without an efficient means to increase the velocity of the wind ultimately hitting the fan blades, a wind system is not practical.
In the locations where wind strength does routinely exceed 10 m.p.h. it is found that the winds in these locations occasionally are excessive. Any system which is designed to make use of average winds must also be capable of withstanding extreme high speed winds.
As set forth above, wind power varies with the cube of the velocity. Also, force exerted on a fan blade at a greater distance from the pivot produces more energy. Thus, the greater the velocity at the greater the distance from the pivot, the greater the energy produced. However, when wind reaches a high speed, excessive lateral distortion is experienced at the fan blade tips as well as excessive tip speed from the high rotational torque.
Prior inventions have addressed the problem of concentrating wind energy. U.S. Pat. No. 3,883,570 by Uzzel, Jr. and German Pat. No. 605377 use a Venturi-shaped chamber which is opened at opposite ends. Venturi-shaped funnels concentrate the wind into the fan which is placed in the chamber. English Pat. No. 2,999 and U.S. Pat. No. 3,878,913 both use a conicle deflector to use wind to the outer portions of the fan blades. However, the above stated patents do not use exteriorally position devices to compress the wind into conical chamber nor do the patents provide for a conical deflector within the chamber whose configuration prevents the backup of air at the fan blades.
German Pat. No. 371,458 and English Pat. No. 507,555 show a tip generation system for the production of energy. The inventors in the above two patents did not seem to use the circumferential production of energy for support of the fan blades about the circumference of the fan. English Pat. No. 507,555 has a generator element located either in front or behind the blades with the blades brushing the poles, differing from this system where at some point the blades are in continuous contact with the circumferential member. The two systems described in German Pat. No. 371,459 and English Pat. No. 507,555 lack the ability to function under very high winds due to the pressure and distortion experienced at the circumference of fan blades which do not have support.
The system needed for development of wind power is a system which can handle extremely high variations of wind velocity and still produce a fairly constant output of power.